Pen



FIG. 1 is a perspective view of a pen showing my new design,

FIG. 2 is a front view thereof,

FIG. 3 is a rear view thereof,

FIG. 4 is a left side view thereof,

FIG. 5 is a right side view thereof,

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines showing the writing tip and attachment structure under the clip are included for the purpose of showing portions of the pen that form no part of the claimed design. 

CLAIM I claim the ornamental design for a pen, as shown and described. 